Force measurements made with a translating holographic optical trap (HOT) of a viscous and a viscoelastic medium are
investigated. In purely viscous media, Stokes drag cannot be measured with a translating HOT with established methods.
In the viscoelastic system of the pericellular coat, the standard force curves generated by a fixed optical trap coupled with
a moving stage can reliably be reproduced by translating HOT experiments. The viscoelastic cell coat provides an
example where slow relaxation dynamics makes force measurements relatively insensitive to differences between
measurements. These preliminary studies suggest that when the relaxation time scale of a system is much slower than
the time scale of the HOT updates, translating HOTs can be reliably used to make force measurements on a viscoelastic, non-equilibrium system.